(i) Field of the Invention
This invention relates a process and tower for continuously cooking comminuted meats.
(ii) Description of the Prior Art
In the processing of meat, it has been proposed in the past temporarily to use a batch process by enclosing a comminuted meat mixture in a mold while subjecting the mixture to a cooking temperature and thereafter stripping the mold from the product. When such meat was processed according to conventional methods, the application of heat was not uniform throughout the mass. Steam cooking or processing subjected the outer portions of the mass to greater treatment than was applied to the central portion. This was because heat applied at the outside must travel through the outer layers to reach the center of the mass. The necessary temperature gradient to produce rapid travel of the heat tended to result in over-treatment of the outer portions particularly if the processing is to be done expeditiously. In canning of foods, this problem has to some extent been resolved by the retortable pouch technology, by which the thickness of the mass through which heat must penetrate has been dramatically reduced, but this has not generally been applied to the continuous processing of meat. Although there are continuous canning methods in use, by and large, however, canning is still a batch process.
In such cooking of meat products as taught by prior art apparatus, either steam or heated water was utilized as the heat-transferring medium. The steam or heated water that was employed as the heat-transferring medium generally moved by convection, or by pumping means, between a reservoir in which the heat was supplied to the heat-transferring medium by a heater and a radiator by which the heat is transferred from the heat-transferring medium to the food articles that were to be cooked.
In the processing of food products, e.g., meat, poultry, and processed meat, e.g., hams, picnics, pork bellies, luncheon meats and sausages, it was thought to be desirable to establish a chamber with a series of different zones, in which different conditions exist. In the past, it has been usual to move the products gradually and progressively and continuously through the various zones in the chamber. Different zones could provide for air circulation, or water shower or water spray treatments. The air may be either at an elevated temperature or may contain smoke or other treatments, or may be at reduced temperature for chilling. Similarly, the water shower may be at an elevated temperature for cooking, or at reduced temperature for chilling. The atmosphere in the chamber may be tempered or modified by regulating the humidity, or by adding artificial smoke.
However, in this prior art procedure, it was necessary to operate the chamber at preset conditions in the various zones. Consequently, it was only possible to process one type of product at any given time. In order to change products, it was necessary for the product already in the chamber to be completely processed all the way through, which might take several hours, and then, when the chamber was empty, the conditions could be changed to suit a different product. This type of installation involved a very substantial investment in capital. It was therefore suitable only for processing products in very large volumes.
The usual method of preparing ham for sale in square slices, consisted, in the first place, in trimming and removing some, if not most, of the fatty tissue and curing the remaining lean meat. This cured meat was then stuffed into a pliable film bag, vacuum sealed and placed in a stainless steel holder. This holder, which may be of any shape in cross-section, i.e., square or circular, gave the cooked meat product its shape. The pliable film bag was constructed of materials such that the meat can be thoroughly cooked therein. The film bag prevented the loss of meat juices, such juices contribute to the binding of the meat chunks which results in a uniform slice that did not disintegrate during high speed mechanical slicing. The bag served, in the second place, as the product package once removed from the holder after cooking.
The art is replete with processes and apparatus which were intended to provide for the continuous processing of proteinaceous food products. One such patent is U.S. Pat. No. 2,488,164 patented Nov. 15, 1949 to J. Bowman et al, entitled "Method of Processing Meat Products". The patented process included the first step of forming the mass to be treated into a block. The block of meat was confined in a container, opposite walls of which were electrically conductive and lateral walls of which were substantially electrically non-conductive. High frequency current was passed through the block by way of the conductive walls to raise the central part of the block to processing temperature. External fluid pressure was applied to the container to oppose internal fluid pressure generated by the heat developed in the mass. The inner portion of the mass was maintained for a predetermined time at temperatures high enough to effect processing of the inner portion. The container was then cooled and was then subjected to steam, to process the outer portions of the block, and the container was again cooled.
This patent suffers the disadvantage that it must be performed in a "batchwise" manner.
U.S. Pat. No. 2,953,461 patented Sep. 20, 1960 by J. J. Prohaska, entitled "Meat Treating Apparatus and Method" provided a meat treating apparatus and method for processing and partially cooking meat. The patentee disclosed a method including the steps of continuously delivering the comminuted mixture through a forming horn while simultaneously subjecting the mixture to a high frequency current to produce at least an initial set in the meat mixture. When the mixture formed as above-described passed from the exit end of the forming horn, it was severed into equal length links, which could then be disposed upon a conveyor to be carried through any further processing needed. The patented apparatus included a tube, which was formed of an electrical non-conductor, which had an inlet, an outlet, and a smooth interior surface. Means were provided for filling and continuously feeding a comminuted meat product into the tube. Means were provided for surrounding the confines of the tube. The surrounding means extended lengthwise along the tube a sufficient distance to produce the required degree of heating for a sufficient length of time to produce at least a partial cooking and an initial set in the comminuted meat product as it passed from the inlet to the outlet.
While this patent disclosed a method and apparatus for the continuous processing of meat, there was no disclosure of the cooling of the meat after the meat was cooked.
U.S. Pat. No. 3,247,777 patented Apr. 26, 1966 by O. Kleppan, entitled "Apparatus for Continuous Predrying, Smoking, Boiling and Cooling of Edibles, Particularly Sausages" provided an apparatus for continuously predrying, smoking, steam cooking and cooling sausages. The patented apparatus included a vertically-elongated, substantially-closed casing, having a plurality of partitions dividing the casing into vertically-elongated compartments, namely an access compartment, a drying compartment, a smoking compartment, a steam cooking compartment, and a cooling and washing compartment. Adjacent ones of the compartments intercommunicated with each other through relatively small passageways to minimize mixing of gases between adjacent compartments. A continuous endless conveyor was provided for holding the sausages passing through all of the compartments. Means were provided for driving the conveyor to cause the sausages to pass sequentially at a constant speed through the compartments. The conveyor passed through the access compartment for loading the sausages on the conveyor and for removing the same therefrom after treatment. Guideways were provided for guiding the conveyor upwardly and then downwardly through the drying compartment for guiding the conveyor through the smoking compartment, for guiding the conveyor up into and then down from the steam cooking compartment, for supplying steam to the steam compartment, and for guiding the conveyor through the cooling and washing compartment. A conduit was provided for supplying hot dry air to the drying compartment. Ducts were provided for supplying gases to the smoking compartment for smoke treatment of the sausages. A smoke outlet was provided at the top of the drying compartment for simultaneously venting the hot air and the gases, so that the hot air was prevented from entering the smoking compartment. Means were provided for injecting a water spray into the cooling and washing compartment.
While this patent taught continuous processing of meat, it suffered the disadvantage that the heating was by direct gaseous contact, with its consequent difficulty of control.
U.S. Pat. No. 3,473,465 patented Oct. 21, 1969 by J. A. Tonjum, entitled "Apparatus for Pressing and Smoking Meat" provided an apparatus for compressing and smoking chunks of meat, e.g., ham. The patented apparatus included a plurality of similar article-supporting units which were interconnected together for movement between expanded and collapsed conditions. Each article-supporting unit or rack was arranged and constructed to cooperate with other racks effectively to compress the ham prior to smoking. Mechanism was provided which was engageable with the racks to compress the racks and also which was operable to elevate the racks to an expanded suspended position for ready transfer of the trolley which supported the racks to a track, so that the racks may be moved through a smoking chamber.
While this patent taught continuous processing of meat, it only taught the compressing of the ham prior to smoking.
U.S. Pat. No. 4,210,675 patented Jul. 1, 1980 by B. E. Liebermann, entitled "Method of Transferring Heat to Food Articles" provided a method of, and an apparatus for, transferring heat to food particles. The patented method included the step of supporting food articles on a support located within a chamber, and forcing a heated liquid heat-transferring medium through a heat exchanger located adjacent to the support. The cooked meat was stored in a chamber having a closure intended to be repeatedly and frequently opened and closed. The cooked meat food articles were supported on a support located within the chamber. A heated liquid heat-transferring medium was forced through a radiator located adjacent to, and on opposite sides of, the support. The humidity within the chamber was maintained above that of the atmosphere outside of the chamber.
The patented apparatus included a chamber, and a support for supporting food articles within the chamber. A reservoir was provided for containing a liquid heat-transferring medium. A heater was provided for heating the liquid medium contained in the reservoir. A radiator was provided which was located adjacent to the support means. Hollow conduits were provided to connect fluid in the reservoir and with fluid in the radiator. A pump was provided for circulating the liquid medium between the reservoir and the radiator. Controls were provided which were connected to the heater for controlling the temperature to within .+-.5.degree. F. of the desired temperature to which the liquid medium was to be heated and maintained by the heater.
While this patent disclosed a method and apparatus for the continuous processing of meat, there was no disclosure of the cooling of the meat after the meat was cooked.
U.S. Pat. No. 4,265,922 patented May 5, 1981 by T. Tsuchiya et al, entitled "Induction Heating Method for Processing Food Material" provided for the treating or processing of food materials under heat and pressure. The patented method included the step of introducing food material into one end of a metallic barrel, and discharging the food material from the other end of the barrel while rotating the barrel. At least a portion of the barrel was inductively heated at a relatively low frequency as it rotated so that heat was first induced in the barrel and was then transmitted by conduction from the barrel into the food material as the food material passed through the barrel. The barrel was rotated within a pair of solenoid-type coils to provide the inductive heating by individually energizing the coils. The temperature of the outer surface of the barrel was sensed at two longitudinally-spaced locations as the barrel rotated and each of the two induction coils was individually controlled in accordance with the temperature that is desired. The coil nearer the discharge end could be energized with more current than the other coil, thereby permitting the discharge end of the barrel, where there was more food material, to be heated to a greater degree than the inlet end.
While this patent taught continuous processing of meat, it suffered the disadvantage that there was no teaching of the cooling of the cooked meat.
U.S. Pat. No. 4,644,857 patented Feb. 24, 1987 by G. E. Buller-Colthurst, entitled "Food Processing Chamber" provided a processing apparatus which included a chamber defining a plurality of chamber zones. Predetermined processing conditions were provided in different chamber zones. A continuous conveyor extended through the chamber zones and defined a single conveyor axis. Unit supports were supportable on the conveyor at spaced intervals, for moving units through the chamber zones. Unit movement devices were operable in steps at predetermined time intervals to move a first unit along the axis of the conveyor at predetermined first time intervals and to move a second unit along the same axis of the conveyor at predetermined second time intervals. Engagement devices were selectively inter-engageable between the unit supports and the movement devices whereby a unit support could be engaged and moved either at first, or at second time intervals. Controls were provided to control the movement devices for selective timed operation.
While this patent disclosed a method and apparatus for the continuous processing of meat, there was no disclosure of the cooling of the cooked food after the food was cooked.
U.S. Pat. No. 4,994,294 patented Feb. 19, 1991 by B. Gould, entitled "Temperature Controlled Food Processing Apparatus and Method" provided an apparatus for processing food products including a rotatable container mounted on a frame structure. The apparatus included spiral fins which were disposed in the interior of the container for imparting movement to the food products along an axis of rotation of the container when the container was rotated about the axis of rotation. A temperaturecontrolling fluid was introduced into contact with the spiral fins to effect heat transfer between the fin surface area and the food products without direct contact between the food products and the temperature-controlling fluid. This controlled the temperature of the food processing operation.
While this patent taught continuous processing of meat, it suffers the disadvantage that there was no teaching of the compression of the meat while it was being continuously cooked.
U.S. Pat. No. 5,008,123 patented Apr. 16, 1991 and its corresponding Canadian Patent Application Serial No. 2,018,338 published Dec. 15, 1990 by D. R. Bewley et al, entitled "Food Processing Method" provided a method for cooking meat in a sealed cooking vessel. The patented method included introducing meat into a mobile cooking vessel and sealing the meat-containing vessel from the atmosphere. A stock liquor was heated with a heat exchanger to a cooking temperature of at least 60.degree. C. and the heated stock was circulated liquor through the vessel and through the heat exchanger for a period of time sufficient to heat the meat to a cooking temperature and to cook the meat. After cooking the meat, the circulating stock liquor was cooled with the heat exchanger to a temperature suitable to cool the cooked meat to a temperature of no more than 15.degree. C. within 45 minutes.
While this patent taught the processing of meat, it suffered the disadvantage that the processing was batchwise, with its consequent difficulty of maintaining high productivity.
U.S. Pat. No. 5,075,120 patented Dec. 24, 1991 by S. G. Leary et al, entitled "Method of Cooking a Food Product in a Process Vapour at Progressively Varying Rates", provided a method for cooking food in an oven. The patented method included passing food products into the housing upon a conveyor of generally permeable construction. A cooking process vapour was applied to the food products in a first cooking zone, the cooking process vapour being circulated parallel to the path of conveyor movement. The food product was moved from the first cooking zone to a second cooking zone. A cooking process vapour was applied thereon to the food product in a direction laterally of the path of conveyor movement. The cooking process vapour was then moved in a direction parallel to the path of conveyor movement. The cooking process vapour was then reheated in the second zone separately from reheating the cooking process vapour in the first cooking zone.
While this patent disclosed a method and apparatus for the continuous processing of food, there was no disclosure of the cooling of the food after the food was cooked.
Canadian Pat. No. 173,733 patented Dec. 12, 1916 by G. N. Luhrmann et al, entitled "Apparatus for Processing or Treating Foods" provided an apparatus and method for the maintenance, within a retort, of any require definite temperature and pressure that may be necessary with any particular food. It also provided an adjustment device so that any particular relation between pressure and temperature could be predetermined and provided for. The meat was cooked in the retort by steam and by compressed air in direct contact with containers containing the meat in the retort. After cooking, the meat in the containers was cooled by warm water (which has been warmed by contact with waste steam) and cold air.
While this patent taught continuous processing of meat, it suffered the disadvantage that the heating was of canned meats and was by direct air/steam contact, with its consequent difficulty of control.
Canadian Pat. No. 413,360, patented Jun. 22, 1943 by S. L. Komarik, entitled "Production of Canned Ham" provided a procedure for the cooking of raw ham while the ham was in a sealed can. The method included the first step of heating the can from a chill temperature of about 40.degree. F. by exposing the ham to a temperature of 115.degree. to 120.degree. F. until the coldest part of the ham attained a temperature of 90.degree. to 95.degree. F. The next step involved heating the can by exposing it to a cooking temperature upwardly from 190.degree. F. for 35 to 40 minutes less about 1/2 minute for each degree over 190.degree. F. The temperature was at least 20.degree. F. higher than the temperature to which the can was later heated. Finally the can was heated by exposure to a temperature which was not over 180.degree. F. but was not under 165.degree. F. until the coldest part of the ham attains a temperature in the range from 152.degree. to 160.degree. F.
While this patent disclosed a method and apparatus for the processing of meat, it suffered the disadvantage of cooking within a sealed can.
Canadian Pat. No. 921,320, patented Feb. 20, 1977 by E. H. Cornwell, "Coagulated Chunks in Canned Meat" provided a continuous method for preparing coagulated meat chunks which were automatically surrounded by the congealed fats and meat juices. The first step in this continuous process was comminuting fresh meat to a cross-section of between 1/16 to 3/4 inch. The next step involved continuously forcing the coarsely comminuted meat through a forming zone thereby compacting each meat particle into intimate contact with the other surrounding meat particles. At the same time as the meat was compacted, it was heating to an internal temperature of at least 120.degree. F. from a heat source which surrounded the forming zone for a time sufficient to coagulate the meat proteins. The next step involved reducing the coagulated meat to a desired particle size. The next step involved mixing the coagulated meat particles with the liquid fat and meat juices which had been separated during the coagulation step. The final step involved chilling the mixture to congeal the liquid fats and juices about the coagulated meat particles in substantially the same ratio as a fresh meat.
While this patent disclosed a method and apparatus for the continuous processing of meat, it suffered the disadvantage of rapid heating to a cooking temperature, followed by rapid cooling to a cool temperature.
Canadian Pat. No. 1,059,830, patented Aug. 7, 1979 by A. Borsuk, entitled "Method and Apparatus for Continuously Making Meat Loaf" provided a method and an apparatus for continuously making a loaf meat product from a stuffable meat material. In the method, magazines of molds were incrementally and sequentially advanced in a closed loop through release agent application, cooking, chilling, knockout and wash stations. A magazine was periodically removed from the closed loop downstream from the release agent application station and was advanced to the stuffing station which was outside the closed loop. At the stuffing station, the molds in the magazine were stuffed with a meat material in loaf form. The magazine was then reinserted into the closed loop upstream of the cooking station.
While this patent disclosed a method and apparatus for the continuous processing of meat, this patent suffered the disadvantage of cooling the meat after the meat was cooked.
Canadian Pat. No. 1,258,401 patented Aug. 15, 1985 by M. Mette, entitled "Apparatus for Continuously Cooking and/or Dehydrating Foodstuffs" provided an apparatus for continuously processing foodstuffs. The apparatus included a preheating zone, a boiling zone and a recooking zone. Each of the zones was arranged separately and had an inlet region and an outlet region. Troughs were installed in each zone. Each zone, moreover, was provided with chambers and was traversed by means for conveying the foodstuffs. A device was provided for introducing hot water to the outlet region of the recooking zone. Another device was provided for removing the water from inlet region of the preheating zone. A heat exchanger was provided for transferring the thermal energy to the water. The inlet region of the recooking zone was connected with the outlet region of the preheating zone by a pipe. A feed pump was intermediately arranged as the means for supplying the water. The feed pump was controlled in accordance with the supply quantity of the water into the recooking zone. A heat exchanger was installed in the boiling zone introducing the water.
While this patent disclosed a method and apparatus for the continuous processing of meat, there was no disclosure of the continuous cooling of the cooked meat.
Canadian Pat. No. 1,263,271 patented Nov. 28, 1989 by P. Choquette, entitled "Process and Apparatus for Cooking and Shaping Meat Slabs" provided a process and an apparatus for cooking and shaping a precut meat piece. The process included the first step of placing an uncooked meat piece adjacent an inlet of a combined shaping mold, and cooking vessel. Then, an air pressure differential was established between the inside and the outside of the shaping mold for driving the meat piece in the shaping mold. Heat was then applied to the meat piece for cooking the meat piece. The apparatus included a shaping mold having an inlet. The combined shaping mold cooking vessel, was adapted to receive an uncooked meat piece. Means were provided in operative relation with the shaping mold to establish an air pressure differential between the inside and the outside of the shaping mold for driving an uncooked meat piece placed adjacent the inlet into the shaping mold. A heater was provided to apply heat to the shaping mold for cooking the meat piece.
While this patent taught continuous processing of meat, it suffered the disadvantage that the cooking was batchwise in an individual mold.